make sure it doesn't accumulate

test/slop/test-slop.sh

@@ -169,7 +169,8 @@ rm obs exp
 
 echo "    slop.t15...\c"
 echo \
-"chr1	159	171" > exp
-echo -e "chr1\t160\t170"| $BT slop -b 0.1 -pct -i - -g ../../genomes/human.hg19.genome > obs
+"chr1	159	171
+chr1	90	210" > exp
+echo -e "chr1\t160\t170\nchr1\t100\t200"| $BT slop -b 0.1 -pct -i - -g ../../genomes/human.hg19.genome > obs
 check obs exp
 rm obs exp